Due to the growing concerns regarding potential biological or chemical terrorist attacks, a need exists in the state of the art for an inexpensive and simple-to-use filter which could effectively remove dangerous contaminated particles from the air within an enclosed space, such as a room in a home, a school class room, an office, and a vehicle, for example, while simultaneously providing a positive pressure within the enclosed space sufficient to prevent migration of the contaminated particles through small cracks or openings that may be present between the enclosed space and outside of the space.
Duct tape and plastic sheeting covering doors and windows provide some protection from airborne contaminants; however, such measures will not provide an airtight seal for particles as small as about 1.0 micron in diameter (about the size of an anthrax spore, for example)). Thus, creating a positive pressure within the enclosed space, in accordance with the present invention, minimizes the introduction of such contaminants into the enclosed space.